Ball valve with integral seal retraction

ABSTRACT

A ball valve is disclosed herein. The ball valve can include a non-planar seal disposed upon a rotating ball, the ball and seal contained within a housing, wherein the seal includes a first section and a second section, the first section oriented at a different angle than the second section. The ball valve can further include a mating surface disposed within the housing adjacent to the ball, the mating surface arranged to fully contact the seal when the ball valve is in a closed position, the mating surface including a first section and a second section, the first section oriented at a different angle than the second section. The seal and mating surface can be oriented so that the first section of the seal does not contact the second section of the mating surface when the ball is rotated between a closed position and an open position.

TECHNICAL FIELD

Embodiments herein relate to the field of fluid control, and morespecifically, to a ball valve with a ball and seal arrangement where theseal does not contact the housing of the valve during actuation.

BACKGROUND

Valves are essential devices to control the flow of various fluids in avast array of applications. The fundamental structure of a basic valveincludes a body with inlet port for receiving a fluid, an outlet portfor discharging the fluid, and a regulating structure contained withinthe body for controlling the flow of fluid between the inlet and outletports. Valves come in an array of different types, typically based ondesign aspects such as the method of valve closure, method of actuation,and configuration of the closing mechanism. For example, butterflyvalves typically employ a disc structure that is mounted to a shaft,thereby allowing the disc structure to rotate between a closed position,where the disc fully obstructs flow from the inlet port to the outletport, to an open position, where the disc is oriented to allow full flowfrom the inlet to the outlet. A handle, disc, lever, or other similarcontrol structure accessible outside of the valve body is mechanicallycoupled to the closing mechanism (such as the disc structure), to allowthe closing mechanism to be manipulated between closed and openpositions. Depending upon the valve implementation, the controlstructure may also allow the valve opening to be sufficiently modulatedto control the rate at which fluid flows through the valve.

A ball valve, as the name suggests, utilizes a roughly spherical bodywith a central passageway that rotates within the valve body. The valveis opened by rotating the ball, via the aforementioned controlstructure, so that the central passage in the ball aligns with the inletand outlet ports, thereby allowing fluid to flow into the inlet port,through the central passage, and out from the outlet port. When the ballis rotated to a closed position, the central passage is typicallyaligned perpendicular to the inlet and outlet ports, with sides of theball blocking the inlet and outlet ports to prevent fluid flow. Ballvalves can provide positive and reliable sealing when closed. The use ofa ball as a sealing mechanism can allow a ball valve to effectivelycontrol a high-pressure flow. Moreover, because the central passage of aball valve is typically oriented perpendicular to the fluid flow whenthe valve is closed, moving the valve to fully open typically requiresonly a quarter turn of the control structure (assuming no gear reductionis employed). As a result, ball valves may be ideal for use inapplications where high-pressure fluid flow must transition rapidly fromcut off to a full flow. For purposes of this disclosure, the term“fluid” is intended to include fluids in a liquid phase, gaseous phase,supercritical phase, or a combination of any of the foregoing.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be readily understood by the following detaileddescription in conjunction with the accompanying drawings and theappended claims. Embodiments are illustrated by way of example and notby way of limitation in the figures of the accompanying drawings.

FIG. 1 is a cross-sectional view of an example ball valve with a sealand seal seat configured to minimize contact during valve manipulation,according to various embodiments.

FIG. 2 is a cross-sectional view of the ball and housing of FIG. 1 withthe example ball in an open configuration, according to variousembodiments.

FIG. 3 is a cross-sectional view of the ball and housing of FIG. 1 withthe example ball in a closed configuration, according to variousembodiments.

FIG. 4 is a side elevation view of a ball, such as may be used in theexample ball valve of FIG. 1, illustrating the seal geometry, accordingto various embodiments.

FIG. 5 is a perspective view of a seal seat, such as may be used in theexample ball valve of FIG. 1, illustrating the seat geometry, accordingto various embodiments.

FIG. 6 is a perspective view of the ball of an example ball valve in anopen configuration, with the valve body shown in cross section,illustrating the seal arrangement on the ball, according to variousembodiments.

FIG. 7 is a perspective view of the ball of FIG. 4 with the example ballin a closed configuration, according to various embodiments.

FIG. 8 is a series of cross-sectional views of various seals,illustrating different possible embodiments of the seal.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof, and in which are shownby way of illustration embodiments that may be practiced. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope. Therefore,the following detailed description is not to be taken in a limitingsense, and the scope of embodiments is defined by the appended claimsand their equivalents.

Various operations may be described as multiple discrete operations inturn, in a manner that may be helpful in understanding embodiments;however, the order of description should not be construed to imply thatthese operations are order dependent.

The description may use perspective-based descriptions such as up/down,back/front, and top/bottom. Such descriptions are merely used tofacilitate the discussion and are not intended to restrict theapplication of disclosed embodiments.

The terms “coupled” and “connected,” along with their derivatives, maybe used. It should be understood that these terms are not intended assynonyms for each other. Rather, in particular embodiments, “connected”may be used to indicate that two or more elements are in direct physicalcontact with each other. “Coupled” may mean that two or more elementsare in direct physical contact. However, “coupled” may also mean thattwo or more elements are not in direct contact with each other, but yetstill cooperate or interact with each other.

For the purposes of the description, a phrase in the form “A/B” or inthe form “A and/or B” means (A), (B), or (A and B). For the purposes ofthe description, a phrase in the form “at least one of A, B, and C”means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).For the purposes of the description, a phrase in the form “(A)B” means(B) or (AB) that is, A is an optional element.

The description may use the terms “embodiment” or “embodiments,” whichmay each refer to one or more of the same or different embodiments.Furthermore, the terms “comprising,” “including,” “having,” and thelike, as used with respect to embodiments, are synonymous, and aregenerally intended as “open” terms (e.g., the term “including” should beinterpreted as “including but not limited to,” the term “having” shouldbe interpreted as “having at least,” the term “includes” should beinterpreted as “includes but is not limited to,” etc.).

With respect to the use of any plural and/or singular terms herein,those having skill in the art can translate from the plural to thesingular and/or from the singular to the plural as is appropriate to thecontext and/or application. The various singular/plural permutations maybe expressly set forth herein for sake of clarity.

When a ball valve is in a closed position, typically only a portion ofthe ball faces the outlet port. The remainder of the ball, including thecentral passage, may be exposed to fluid and to any pressure imposed bythe stopped flow of the fluid from the inlet port. The area of theremainder of the ball is typically greater than the area facing theoutlet port. This asymmetry can result in the ball being biased againstthe outlet port by the upstream pressure, helping to further seal thevalve and prevent any leakage. In a typical ball valve, the outlet portand/or the inlet port may further include a seat that is machined orotherwise formed to fit to the outer surface of the ball, to helpimprove the valve seal.

This biasing force, in some ball valves, may be sufficient to fully sealthe ball from leakage or seepage, particularly where the ball fitsclosely with the seat. In other ball valves, either the ball, the seat,or both may be equipped with a seal or seals to help improve theintegrity of the valve in resisting leaks or seepage. Regardless ofwhether a seal is present, rotating the ball between open and closedpositions typically results in the ball and/or seal (depending onwhether the seal is disposed on the ball or on the seat) rubbing againstat least the seat, and possibly other portions of the housing interiorand inlet port. Over time, this rubbing can result in wear on the sealand/or ball, as well as the seat and/or other components of the housing.This wear can increase the clearance between the ball and theseat/outlet port, and eventually result in leakage. In ball valves thatinclude an elastomeric seal, the seal may be the only component subjectto significant wear. Depending upon the ball valve construction, theseal may be a serviceable item that can be replaced, greatly extendingthe ball valve's life. However, replacing the seal may still imposedowntime on the equipment relying upon the ball valve. Thus, minimizingseal wear can minimize downtime and/or reduce the risk of premature sealfailure, which may be crucial where the ball valve is employed incritical applications.

Seal wear can be reduced by minimizing the amount of that the sealcontacts an opposing surface. A variety of different approaches havebeen attempted. For example, some ball valves may employ a mechanismthat couples to the ball or an attached component that rotates with theball, such as a valve stem. Rotating the ball away from the closedposition simultaneously actuates a mechanism that retracts the seal awayfrom the ball as the ball begins it travel, so that seal contact isminimized. Similarly, while the ball is being rotated back to the closedposition, the seal is kept retracted until near the end of the ball'stravel, where the retraction mechanism extends the seal as the ballreaches a fully closed position. While such an approach can reduce sealwear, it also introduces a point of failure in the relatively complexretraction mechanism. Depending upon the seal and ball geometry, if themechanism fails to retract the seal, the ball may be difficult orimpossible to move. Similarly, if the mechanism fails to extend theseal, the valve may leak when in a closed position.

Another possible solution involves mounting the ball eccentrically, sothat the body of the ball inscribes a circle, rather than the ballrotating about an axis. When combined with a valve housing that has aninternal cavity with a radius that is greater than the circle inscribedby the ball, the ball effectively retreats away from the housinginterior as it rotates away from a closed position. Thus, the seal hasminimal contact with the seat, coming into contact only within the lastfew degrees of travel to the closed position. However, such a solutionrequires an oversized interior cavity within the valve housing, whichincreases both the overall valve size, as well as the valve weight, dueto the additional material needed for a larger valve housing.Furthermore, such an arrangement generally prohibits any valveconfiguration that may have double seals, e.g. a seal and seat aroundboth the inlet and outlet ports.

In any of the foregoing examples, the seals and seats are annular, andplanar. Specifically, the seals and seats define a single plane, as istypical in known ball valves. Disclosed embodiments include a ball valvethat rotates about an axis, with a seal and seat that are asymmetric ingeometry. Specifically, the seal and seat do not lie within a singleplane, but have a portion of the seal and seat that is set at adifferent angle than another portion of the seal and seat. By orientingthe leading edge of the seal (defined as the portion of the seal thatadvances first toward the outlet port as the valve is rotated to theclosed position) at a steeper angle relative to the trailing edge of theseal, seal contact against the seat is limited only to the last fewdegrees of ball travel, minimizing wear. No separate retractionmechanism is needed. Because the ball is positioned to rotate about acenter axis, the valve housing can be kept relatively close to the ball,as the space needed to accommodate the travel path of an eccentricallymounted ball is unnecessary. Thus, the valve housing can be keptrelatively small, and the risk of failure of a retraction mechanism iseliminated.

Referring to FIG. 1, a cross-section of an example ball valve 100according to various embodiments is depicted. Ball valve 100 includes avalve housing 102, and a ball 104 that is positioned within a cavity124. In the depicted embodiment, a seal 106 is retained to ball 104 witha retainer 112. The seal 106 contacts a seal seat 108 at a mating orseal contact surface 110. The ball 104 is rotated between open andclosed positions via a valve stem 114. In the closed position, asdepicted in FIG. 1, the seal 106 is in contact with contact surface 110of seat 108. Rotating the ball 104 to an open position (depicted in FIG.2, discussed below) aligns a center passage 116 with the inlet port 118and outlet port 120, thereby allowing a fluid to pass from inlet port118, through the center passage 116, and out from outlet port 120. Theretainer 112, in the depicted embodiment, is retained to the ball 104via multiple fasteners, including fasteners 122 a, 122 b, and 122 c(collectively or generically, 122).

Housing 102 encloses various components of the ball valve 100, and mayprovide one or more mounting points for securing ball valve 100 to anadjacent structure. Housing 102 may be implemented as one or morepieces, and may facilitate servicing of valve components, such as by oneor more removable sections or access ports. Housing 102 may bemanufactured from metal, plastic, composites, or another suitablematerial or combination of suitable materials. Housing 102 likewise maybe manufactured using any suitable technique or techniques appropriateto the materials employed for housing 102, such as casting, forging,machining, or milling.

Within housing 102 a cavity 124 may be formed, for enclosing variousoperative components of ball valve 100, such as ball 104 and itsassociated seal 106 and retaining structures. In embodiments, cavity 124may be sized to closely fit ball 104, with only a minimum of clearanceprovided between the interior wall of cavity 124 and the exteriorsurface of ball 104, sufficient to allow ball 104 and its associatedstructures to rotate with minimal or no contact. Cavity 124 may beformed by milling or machining, such as where housing 102 is formed froma solid billet or billets of material, or may be cast as part of theforming of housing 102. The cavity 124 may further be refined by millingor machining following forming, to bring cavity 124 into close tolerancewith ball 104 and its associated structures.

Ball 104 is the moving component of ball valve 100 responsible forfluidly coupling the inlet port 118 to the outlet port 120. Ball 104 isessentially spherical in shape. In embodiments, a valve stem 114 isformed or attached to ball 104 along an axis that passes through thecenter of ball 104, defining the ball 104's rotational axis. Thus, inthe depicted embodiment, the ball 104 does not inscribe a circular pathwhen rotated, but generally symmetrically rotates about the axis definedby valve stem 114. Valve stem 114, in the depicted embodiment, extendsalong ball 104's axis of rotation, through housing 102, to provide anexternally accessible point outside of housing 102 to rotate ball 104between open and closed positions. Valve stem 114 may also have anextension 126 that extends along the axis rotation distal from valvestem 114 and secures into housing 102, to provide axial stability toball 104. Valve stem 114 and extension 126 may interface with housing102 via a suitable bearing. At least for valve stem 114, in the depictedembodiment, the bearing may be sealed to prevent fluid leakage fromcavity 124 around valve stem 114.

In some embodiments, such as the depicted embodiment, valve stem 114 canaccept an external control, such as a lever or disc, to allow a rotarymotion to be imparted to ball 104 to effect opening or closing of ballvalve 100. In other embodiments, valve stem 114 may be entirelycontained within housing 102, and be actuated by either a mechanicallinkage such as a gear train or drive, or may be actuated by a mechanisminternal to ball valve 100, such as a hydraulic or electrical actuator.In still other embodiments, valve stem 114 may be omitted, with ball 104being driven between open and closed positions by a discrete mechanism,such as a gear drive that interfaces with a gear or other suitable meansfor transfer of rotational force that may be affixed to ball 104. Insome such embodiments, extension 126 may be equipped to ball 104, andmay be equipped to receive rotational force for driving ball 104 betweenopen and closed positions.

Referring to FIG. 2, a cross-section view of ball valve 100 in an openconfiguration, ball 104 further includes a central passageway 116, whichacts to fluidly couple inlet port 118 to outlet port 120 when ball 104is rotated to an open position. Central passageway 116 is a straight,round bore in the embodiments depicted in FIGS. 1 and 2, owing to thepositions of inlet port 118 and outlet port 120, which are orientedalong a longitudinal axis. In other embodiments, inlet port 118 andoutlet port 120 may be offset from each other. In such embodiments,central passageway 116 may be configured with a curve or a bend, as maybe necessary to fluidly couple inlet port 118 to outlet port 120. Forexample, in an embodiment where inlet port 118 and outlet port 120 areoriented at a 90 degree angle, central passageway 116 may be configuredas either a 90 degree bend or 90 degree curve. Although depicted as around bore with approximately the same diameter as inlet port 118 andoutlet port 120, it should be understood that central passageway 116 maybe of any cross-section and size appropriate for a given implementation.Central passageway 116 need not be of the same cross-section and/or sizeas either of inlet port 118 or outlet port 120. In some embodiments,central passageway 116 may have a relatively complex interior, as may benecessitated for a given implementation to effect proper control overfluid flow.

Ball 104 may be constructed from any material or materials suitable fora given implementation, such as metal, plastic, ceramic, composites, orany other suitable material. Valve stem 114 and/or extension 126 may beformed as part of, and integral with, ball 104, or may be formed asdiscrete components that are attached to ball 104. Central passageway116 may be formed during formation of ball 104, such as where ball 104is formed via molding, forging, or casting, or may be formed via millingor machining, such as when ball 104 is initially cast or molded as asolid sphere or is formed from a solid billet of material.

In the example embodiments depicted herein, seal 106 is substantiallyannular in shape. Seal 106 is retained to the surface of ball 104, inembodiments, in a position that causes it to circumscribe outlet port120 when closed. In the depicted embodiment, seal 106 is oriented to lieapproximately parallel to a plane defined by the axis of rotation and alongitudinal axis through central passageway 116. Seal 106 may beretained to the surface of ball 104 via retainer 112. Retainer 112, inturn, may be secured to ball 104 via a plurality of fasteners 122. Theuse of fasteners 122 to secure retainer 112 to ball 104 can allow seal106 to be replaced relatively easily during servicing of ball valve 100.In other embodiments, retainer 112 may be integral with seal 106, viz.seal 106 may be a single part that is directly secured to ball 104, suchas with one or more fasteners 122, or another suitable retentiontechnique. In some embodiments, seal 106 may cooperate with retainingfeatures on ball 104, to allow seal 106 to be retained in place on ball104 without the need for a separate retainer 112, or even fasteners 122.Seal 106 and retainer 112 will be discussed in greater detail below.

As seen in FIG. 1 and in FIG. 3, a cross-sectional view of the ball in aclosed position, seal 106 may seal against a valve seat 108, inembodiments. Valve seat 108 may be a separate piece from housing 102that is fit into place, and is retained via a press-fit, one or morefasteners, and/or one or more retaining devices, depending upon theneeds of a given implementation. In other embodiments, valve seat 108may be integral with, and formed into or from, housing 102, as part ofoutlet port 120. Seal 106, in the depicted embodiment, contacts valveseat 108 at a contact surface 110. Valve seat 108 will be discussed ingreater detail below.

As may be seen in FIGS. 1-3, seat 108 may form at least part of outletport 120. In the depicted embodiment, seat 108 acts as a liner formingthe interior surface of outlet port 120. In the depicted embodiment,inlet port 118 lacks a liner or structure that corresponds to seat 108for outlet port 120. However, some embodiments of ball valve 100 mayinclude a second seal and seat that circumscribe inlet port 118. In suchembodiments, ball 104 may have a seal 106 disposed on either side ofcentral passageway 116, with each seal 106 mating to a seat 108 disposedaround the inlet port 118 and outlet port 120, respectively. In suchembodiments, materials may be used for seal 106 and/or seat 108 forinlet port 118 that are different from the materials for seal 106 and/orseat 108 for outlet port 120. It should further be understood that, insome embodiments, ball valve 100 may be reverse-oriented so that outletport 120 acts as inlet port 118, viz. fluid flows into port 120, whichbecomes an inlet port, and discharges from port 118, which becomes anoutlet port, with seal 106 disposed annularly around port 120 as aninlet port.

Fluid flow is indicated by arrows in FIGS. 1-3 (as well as FIGS. 6 and7, discussed below) corresponding to the inlet port 118 and outlet port120. When ball valve 100 is closed, inlet port 118 may be subject to ahigh pressure relative to outlet port 120. In embodiments where ballvalve 100 is reverse-oriented, it should be understood that the arrowswould be reversed, where outlet port 120 is subject to a high pressurerelative to the inlet port 118. In some embodiments, the valve is flowagnostic, e.g. capable of functioning with flow from either direction,and either the inlet port 118 or outlet port 120 being pressurizedrelative to the other port. In other embodiments, the seal 106 may needto be reconfigured to ensure proper sealing and valve operation in areverse flow implementation.

FIG. 4 depicts a side profile view of an example embodiment of seal 106geometry as secured to ball 104. Seal 106, in the depicted embodiment,includes a first section 206 and a second section 208, separated by atransition zone 210. It should be understood that first section 206 andsecond section 208 each comprise an arcuate portion of seal 106, witheach end of the arcuate portions separated by a transition zone 210.Thus, in the depicted embodiment, there are two transition zones 210diametrically opposed on seal 106. Due to the side elevation view, thesecond transition zone is not visible. First section 206 of seal 106 maybe oriented at a first angle 212 that is acute relative to a radiallyextending line (indicated in long dashes), and relative to a tangentline defining the direction of travel of an outer point on the sphericalsurface of ball 104. Second section 208 of seal 106 may be oriented at asecond angle 214 that is also acute relative to a radially extendingline (indicated in long dashes interspersed with dots), but closer toninety degrees compared to first angle 212. First angle 212 and secondangle 214 define seal path angles for first section 206 and secondsection 208, respectively. In various embodiments, for both first angle212 and second angle 214, any angle could be practically implemented, upto and including 90 degrees, depending upon the requirements of aspecific implementation, e.g. as dictated by seal and seat geometry andconfiguration.

In transition zone 210 of the depicted embodiment, the first angle 212of first section 206 transitions smoothly to the second angle 214 ofsecond section 208. The rate at which the angle transitions, and hencethe size of transition zone 210, will depend upon the particulars of agiven embodiment. One of the transition zones 210 may differ in size andrate of angular change from the other transition zone 210, in someembodiments. The transition zones 210, in embodiments, maintain atangential angle as viewed from a top plane around the entirecircumference of the sealing face, e.g. the seal 106 and thecorresponding angled portions of ball 104 adjacent to seal 106 that mateto seat 108. In some embodiments, first angle 212 and second angle 214are consistent at all points across the sealing circumference. Thechange in radius (as viewed from the top) in each transition zone 210serves to provide a consistent angle at the top and bottom of thesealing face that first angle 212 and second angle 214 may not otherwiseprovide in those locations. Generally, the more gradual the transition(and larger the transition zone 210), the less the wear to the seal 106in the transition zone 210, as a more continuous transition (e.g.gradual) minimizes wear by providing all points on the circumferentialseal 106 with the same approach angle while minimizing abrupt radiichanges of the seal path. Carried to its logical extension, seal 106 andball 104 may be configured, in some embodiments, with a completelyparametric seal path with no distinguishable transition zones, e.g.transition zone 210 essentially spans the entire path of seal 106 aboutball 104, such that angle varies continuously between first angle 212and second angle 214. The amount of the first and second angles 212, 214and their variance relative to each other may vary depending upon thespecifics of a given implementation, such as the size of ball 104 andthe diameter of the annular seal 106 relative to the diameter of ball104.

To ensure that seal 106 both makes complete and sufficient contact withcontact surface 110 of seat 108 and likewise clears seat 108 when ball104 is rotated to an open position, first section 206 and second section208 of seal 106 are offset from the spherical surface of ball 104. Ascan be seen in the embodiment depicted in FIG. 2, first section 206protrudes from the surface of ball 104 via a ridge 202, which extends atan obtuse angle relative to a radial line. Ridge 202 tapers down throughtransition zone 210, to form a shallow lip 204 in second section 208. Itmay be observed that seal 106, by virtue of ridge 202 and lip 204, iseffectively raised above the spherical surface of ball 104. As may beseen in the embodiment depicted in FIG. 2, both first section 206 andsecond section 208 approximately bisect an arc defined by the travelpath of the direction of motion of ball 104. As lip 204 is lower thanridge 202, second portion 208 lies in a different plane than firstportion 206, rendering seal 106 asymmetric. Moreover, the configurationof first section 206, second section 208 at a different angle from firstsection 206, and intervening transition zone 210, results in anon-planar seal 106 with a slight twist that nevertheless is capable ofcompletely sealing against seat 108 when ball valve 100 is in a closedposition.

Seal 106 may be formed with an elastomeric material, and may be of avariety of different cross sections. Seal 106 is disposed upon ball 104in a relatively complex geometry to minimize wear of seal 106 when ballvalve 100 is actuated between open and closed positions.

FIG. 5 depicts an example embodiment of seat 108, and specifically,contact surface 110. Similar to seal 106 on ball 104, in the depictedembodiment contact surface 110 of seat 108 includes a first section 302and a second section 304. First section 302 and second section 304 eachare arcuate in shape. First section 302 is separated from second section304 by transition zones 306 a and 306 b, which are diametrically opposed(collectively or generically, transition zone 306). The angles at whicheach of first section 302 and second section 304 are disposed may bemirrors of the angles of first section 206 and second section 208,respectively, of seal 106, to ensure that seal 106 fully contacts andseals against contact surface 110. As with transition zones 210 of seal106, discussed above with respect to FIG. 4, the angular transitionbetween first section 302 and second section 304 may be gradual orrelatively abrupt, the rate of transition over distance determining thesize of each transition zone 306. In some embodiments, transition zone306 a may be of a different size and rate of angular change thantransition zone 306 b.

In the depicted embodiment, first section 302 includes a plurality ofcut-outs, including cut-outs 308 a, 308 b, 308 c, and 308 d(collectively or generically, cut-out 308). The cut-outs, as may beseen, extend from an outer surface of seat 108 partially into contactsurface 110 within first section 302. Similarly, second section 304, inthe depicted embodiment, includes a plurality of cut-outs, includingcut-outs 306 a, 306 b, 306 c, and 306 d (collectively or generically,cut-out 306). In contrast to cut-outs 308, cut-outs 306 extend from aninner surface of seat 108 partially into contact surface 110 withinsecond section 304. Cut-outs 306 and 308 extend into their respectivesections only to the extent that they are fully covered by seal 106 whenball valve 100 is in a closed position. As ball 104 rotates to an openposition, seal 106 moves to uncover cut-outs 306 and 308 prior toclearing contact surface 110. As they uncover, the provide a fluidcommunication with cavity 124 which, in embodiments where ball valve 100has a single seal 106 around outlet port 120, may be filled with fluidunder pressure from inlet port 118. This partial release of fluid fromcavity 124 into outlet port 120 may help to release pressure that may bebiasing ball 104 into seat 108. The release of fluid may further assistin breaking the contact of seal 106 with contact surface 110, to helpfree ball 104 to fully rotate to an open position. The number and depthof cut-outs 306 and 308 may vary depending upon the needs of a givenembodiment. Some embodiments may omit cut-outs 306 and/or 308.

Contact surface 110 may be formed to fully contact seal 106 when ballvalve 100 is in a closed position, and to provide minimal friction toseal 106 as seal 106 moves into or out of contact with seat 108. In thisway, wear of seal 106 can be minimized. In embodiments where frequentactuation of ball valve 100 is expected, where seal 106 is of a materialthat may impose wear upon seat 108, and/or where use conditions mayresult in seat 108 experiencing wear, seat 108 may be formed as aseparate piece, to allow for removal and servicing or replacement. Seat108 may be formed from metal, plastic, ceramic, composites, or any othermaterial or combination of materials suitable for a givenimplementation. The choice of materials for seat 108 may be selectedwith respect to the choice of materials used for seal 106.

While the depicted embodiments illustrate an arrangement where seal 106is disposed upon and retained to ball 104, it should be understood thatseal 106 may instead be retained upon seat 108, with ball 104 insteadcarrying contact surface 110. The geometry of ball 104 and seat 108remain unchanged in such embodiments.

Turning to FIGS. 6 and 7, ball valve 100 is depicted in perspective viewof ball 104 with housing 102 in cross-section in open (FIG. 6) andclosed (FIG. 7) positions, to illustrate the interface between seal 106and contact surface 110 in open and closed positions.

Referring to the example embodiment of FIG. 6, ball 104 is illustratedin an open position. Central passageway 116 is oriented to be in lineaxially with inlet port 118 and outlet port 120, to provide a continuouspassage for fluid from inlet port 118 to outlet port 120. Valve stem 114is visible. Seal 106 is retained by retainer 112, and is disposed on theright hand side, facing into cavity 124. Seal 106 and retainer 112 areroughly parallel to the longitudinal axis defined by inlet port 118,central passageway 116, and outlet port 120. FIG. 2, introduced above,shows the example embodiment in cross section, clearly illustrating thefluid connection of inlet port 118, central passageway 116, and outletport 120. As can be seen in FIG. 2, second section 304 of contactsurface 110 is shown protruding into cavity 124, to eventually contactsecond section 208 (indicated in FIG. 6). By virtue of its extendinginto cavity 124 and the position of second section 208 of seal 106,second section 304 of contact surface 110 acts as a travel stop for ball104, preventing further rotation once ball 104 is in a fully closedposition. Also visible in both FIGS. 2 and 6 are cut-outs 306.

FIG. 7 illustrates the example embodiment of FIGS. 1-3 in a closedposition. As can be seen, central passageway 116 is perpendicular to theaxis defined by inlet port 118 and outlet port 120. Inlet port 118 opensonto ball 104, while seal 106 is engaged with contact surface 110 (notvisible) of seat 108. Inlet port 118, in the depicted embodiment, is notsealed by ball 114, but instead is in fluid communication with cavity124. This arrangement is best illustrated in FIG. 3, introduced above.Where fluid coming from inlet port 118 is under pressure, this pressurebears upon all surfaces of ball 104, including central passageway 116,behind seal 106. As the portion of ball 104, including retainer 112,that is exposed to outlet port 120 may not be under pressure, thepressure of fluid from inlet port 118 acts to bias ball 104, and thusseal 106, against seat 108, helping to improve seal function and preventleakage.

In certain embodiments, pressurized fluid from inlet port 118 furthermay act to rotationally bias ball 104 to a closed position. As can beseen in FIG. 7, ridge 202, on the trailing side of seal 106 as ball 104rotates closed, is exposed to cavity 124 when ball 104 is in or near aclosed position. Conversely, the leading edge of seal 106 is protectedfrom cavity 124 by the portion of seat 108 that extends into cavity 124,acting as a travel stop for ball 104. Because the trailing edge of seal106 has a greater area exposed to any pressurized fluid in cavity 124 byvirtue of ridge 202, as will be understood, ball 104 is biased by suchfluid to rotate into a closed position, in addition to an overall biasagainst seat 108. As discussed above, cut-outs 306 and 308 (not shown)help to overcome this bias prior to the seal 106 clearing the contactsurface 110, once seal 106 has moved a few degrees. It will beappreciated by a person skilled in the art that this rotational bias maynot be present where the flow is reversed, e.g. where the outlet port120 is pressurized relative to inlet port 118.

FIGS. 6 and 7 also depict retainer 112 affixed to ball 104, to retainseal 106. Retainer 112, as can be seen, is substantially disc-shaped inthe depicted embodiment, and may include a central depression. Retainer112 may include asymmetric features or have an asymmetric profile, toaccommodate the asymmetric configuration of seal 106 and correspondingseat 108. Retainer 112 may have a different shape in differentembodiments, depending upon the requirements of a given implementation.Retainer 112 may be formed from metal, plastic, ceramic, composites, orany other material or combination of materials suitable for a givenimplementation.

As may be understood from FIGS. 4-7, the differing angles of thecorresponding first and second sections of seal 106 and contact surface110, in embodiments, ensure that the second section 208 of seal 106 doesnot contact the first section 302 of contact surface 110 as the ball 104rotates into a closed position. In embodiments, the geometry of the seal106 and contact surface 110 of seat 108 is arranged so that the firstsection 206 only contacts first section 302, and the second section 208only contacts the second section 304. In some embodiments, this contactmay only occur once ball 104 is within five degrees of a fully closedposition. Thus, seal 106 only is subject to friction or wear forapproximately five degrees of travel to or from a fully closed position.Once past approximately five degrees of travel, seal 106 does notcontact any other structures within ball valve 100, helping to preserveseal life. Other embodiments may limit contact to more or less than fivedegrees of a fully closed position, depending upon the particular anglesemployed for seal 106 and contact surface 110.

Referring now to FIG. 8, example embodiments of the seal are depicted incross section. In cross section (1), seal 801 has a U-shaped crosssection, with an angular protrusion forming the sealing surface. Aspring mechanism (not shown) may be placed within the U-shaped groove tohelp bias seal 801 towards a contact surface. The angular formation ofseal 801 may enhance wiping of the contact surface to help keep thesurface clear of debris that may interfere with seal integrity. In crosssection (2), seal 802 has a C-shaped cross section, with a rectangularprotrusion forming the sealing surface. As with seal 801, a springmechanism may be placed within the C-shaped cross section to help biasseal 802 towards a contact surface. The rectangular protrusion likewisemay help with wiping of the contact surface, and further may provide abetter seal against the contact surface due to the greater surface areapresented by the rectangular protrusion, albeit as the expense ofpotentially greater effort required to close or open the ball valve 100from a fully closed position. In cross section (3), seal 803 issubstantially solid, with a blade protrusion extending away from achannel. As with seal 801, the blade protrusion may provide superiorwiping action of a contact surface, with the underlying channel helpingto trap any contaminants or debris. However, seal 803's improved wipingaction may come at the expense of a greater seal integrity, and so seal803 may be unable to withstand the same amount of pressure as anotherseal configuration. Finally, cross section (4) illustrates a seal 804with a substantially round cross section, similar to the configurationof seal 106 discussed above. A round cross section may offer thegreatest ease in moving ball 104 to or from a fully closed position, atthe expense of reduced wiping action against the contact surface. Thesefour seals 801, 802, 803, and 804 are only a few examples; other sealconfigurations may be employed in various embodiments, depending uponthe needs of a given configuration.

It should be recognized that each of the four seals 801, 802, 803, and804, may be useable with ball 104 and potentially retainer 112, asdiscussed above. A given ball valve 100 may be reconfigured with adifferent type of seal by removal of the retainer 112, and swapping theseal. In some cases, such as seal 802, an additional shim or similarsupport may be added to adapt the seal to retainer 112, or retainer 112may be swapped for a retainer designed to accommodate seal 802. Otherseal configurations may also be useful with ball valve 100, potentiallyby simply swapping retainer 112. In still other embodiments, sealconfigurations may also be changed by swapping out seat 108, if it isremovable from housing 102. In such embodiments, the geometry andsealing characteristics of a given ball valve 100 may be adapted to awide array of uses by configuring the ball valve 100 with theappropriate seal 106, seat 108, and retainer 112.

Seal 106, 801, 802, 803, and/or 803 may be manufactured from anelastomeric material, to allow the seal to conform closely to contactsurface 110. In other embodiments, however, the seal may be manufacturedfrom relatively more rigid materials, such as metal, ceramic, composite,or another suitable material or combination of materials, depending uponthe requirements of the intended use of a given embodiment. Furthermore,the seal may be installed using an additive or machine in place process.Raw seal material may be placed upon ball 104 and retained with retainer112. The seal material may then be machined in place to closely matchthe profile of the contact surface 110. In some such implementations,precise measurements of contact surface 110 may be obtained, and thenused via a CNC process to create a seal that accurately fits to contactsurface 110. Such a process may be of particular use where contactsurface 110 has undergone a degree of wear such that it has drifted fromits original specifications sufficiently that a seal conforming tooriginal specifications may not be able to fully seal, or provide anadequate seal, to the contact surface 110 when the ball is in a fullyclosed position.

As mentioned above, in other embodiments the seal 106 may be secured tothe seat 108, with the contact surface 110 secured to the ball 104. Insuch embodiments, the seal 106 may be installed in raw form to seat 108,which can then be machined in place to match the contact surface 110secured to ball 104.

Although certain embodiments have been illustrated and described herein,it will be appreciated by those of ordinary skill in the art that a widevariety of alternate and/or equivalent embodiments or implementationscalculated to achieve the same purposes may be substituted for theembodiments shown and described without departing from the scope. Thosewith skill in the art will readily appreciate that embodiments may beimplemented in a very wide variety of ways. This application is intendedto cover any adaptations or variations of the embodiments discussedherein. Therefore, it is manifestly intended that embodiments be limitedonly by the claims and the equivalents thereof.

What is claimed is:
 1. A ball valve, comprising: a non-planar sealdisposed circumferentially upon a rotating ball, the ball and sealcontained within a housing, wherein the seal comprises a first sectionand a second section, the first section oriented at a different anglethan the second section; and a mating surface disposed within thehousing adjacent to the ball, the mating surface arranged to fullycontact the seal when the ball valve is in a closed position, the matingsurface including a first section and a second section, the firstsection oriented at a different angle than the second section, whereinthe seal and mating surface are oriented so that the first section ofthe seal does not contact the second section of the mating surface whenthe ball is rotated between a closed position and an open position;wherein the mating surface comprises a plurality of cut-outs configuredto be uncovered by the non-planar seal as the ball is rotated betweenthe closed position and open position, wherein the plurality of cut-outscomprises a first subset of cut-outs disposed within the first sectionof the mating surface and a second subset of cut-outs disposed withinthe second section of the mating surface, and wherein the plurality ofcut-outs are configured to release a biasing pressure from an inlet portof the ball valve when uncovered by the non-planar seal.
 2. The ballvalve of claim 1, further comprising a retaining ring that secures theseal to the ball.
 3. The ball valve of claim 1, wherein the seal doesnot contact the mating surface until the ball is rotated within fivedegrees of the closed position.
 4. The ball valve of claim 1, wherein,when the ball valve is in the closed position, first and second portionsof the ball are exposed to an upstream flow, with the first portionhaving a greater surface area than the second portion such that the ballis biased towards the closed position when pressurized by the upstreamflow.
 5. The ball valve of claim 1, wherein the seal is a first seal andthe mating surface is a first mating surface, and further comprising: asecond non-planar seal; and a second mating surface arranged to fullycontact the seal when the ball valve is in a closed position.
 6. Theball valve of claim 5, wherein the first seal and first mating surfaceare disposed about an outlet port, and the second seal and second matingsurface are disposed about an inlet port.
 7. The ball valve of claim 1,wherein the seal and mating surface are annular in configuration, anddisposed about an outlet port.
 8. A method for constructing a ballvalve, comprising: disposing, within a valve housing, a seal seat, theseal seat including a first section and a second section, the firstsection being non-planar with the second section; and retaining, upon aball contained within the valve housing, an elastomeric seal into afirst section and second section, the first section being non-planarwith the second section such that the elastomeric seal iscircumferentially disposed about the ball, disposing a plurality ofcut-outs within the seal seat, wherein a first subset of the pluralityof cut-outs are disposed within the first section of the seal seat, andwherein a second subset of the plurality of cut-outs are disposed withinthe second section of the seal seat; wherein the seal seat and seal areoriented so that the first section and second section of the seal fullycontact the first section and second section of the seal seat,respectively, when the ball valve is in a closed position, and the firstsection of the seal does not contact the second section of the seal seatwhen the ball valve is rotated between the closed position and an openposition, wherein the plurality of cut-outs are configured to beuncovered by the seal as the ball is rotated between the closed positionand open position, and wherein the plurality of cut-outs are configuredto release a biasing pressure from an inlet port of the ball valve whenuncovered by the non-planar seal.
 9. The method of claim 8, furthercomprising machining the elastomeric seal following retention upon theball to fully contact the seal seat.
 10. The method of claim 8, furthercomprising machining the seal seat following disposing the seal seatwithin the valve housing to fully contact the seal.
 11. The ball valveof claim 1, wherein the first section and the second section eachcomprise different arcuate portions of the seal.
 12. The ball valve ofclaim 1, wherein the seal defines a circumferential axis about therotating ball, and wherein the first section is oriented at a differentangle relative to circumferential axis than the second section, suchthat the first section comprises a first arcuate geometry and the secondsection comprises a second arcuate geometry, and wherein the firstarcuate geometry is different than the second arcuate geometry.